Calculus is ruining my life!

A) For what values of 'x' is f(x) discontinuous?
B) At each point of discontinuity found in part A, determine whether f(x) has a limit and, if so, give the value of the limit.
C) A rational function g(x)= a/(b+x) is such that g(x)=f(x) wherever f(x) is defined. Find the values of 'a' and 'b'.

I think I figured out both part A and B, but part C is killing me. Any help would be great.

A) For what values of 'x' is f(x) discontinuous?
B) At each point of discontinuity found in part A, determine whether f(x) has a limit and, if so, give the value of the limit.
C) A rational function g(x)= a/(b+x) is such that g(x)=f(x) wherever f(x) is defined. Find the values of 'a' and 'b'.

I think I figured out both part A and B, but part C is killing me. Any help would be great.

A function is discontinuous when the y value for a certain x value does not exist. In this case, it would be when the denominator equals zero. That should be pretty simple to figure out.